Method for controlling drum type washing machine

ABSTRACT

A method for controlling a drum type washing machine is provided. The method includes selecting a delicate washing cycle or receiving an input from a user of such a selection; supplying air bubbles into a drum of the washing machine, thus allowing delicate clothing and/or laundry to be moved away or separated from a bottom (e.g., cylindrical) surface of the drum; washing the laundry while rotating the drum in a forward or backward direction by rotating a shaft forwardly or backwardly using rotational force from a driving motor; rinsing the laundry; and removing water from the laundry.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based on and claims priority from Korean Patent Application No. 10-2013-0163883, filed on Dec. 26, 2013, the disclosure of which is incorporated herein in its entirety by reference.

TECHNICAL FIELD

The present disclosure relates to a method for controlling a drum type washing machine, and more particularly, to a method for controlling a drum type washing machine capable of washing delicate clothing and/or material, such as pure cotton or linen, using air bubbles.

BACKGROUND

In general, laundry is put into a drum type washing machine through a door at a front side of the washing machine, and the drum type washing machine washes the laundry using a relatively small amount of water and detergent.

The drum type washing machine includes a cabinet that forms the exterior of the washing machine; a tub that is in the cabinet and that holds wash water therein; a rotary drum that is in the tub and that holds the laundry therein; a motor that is in, adjacent to or under the tub and that provides motive power to the drum; a water supplying device that supplies water to the tub; and a drain that drains the wash water from the tub to the outside of the cabinet after a washing process is completed.

Multiple prominences may be on an inner peripheral surface of the drum, in order to improve the washing effect by allowing the laundry to contact or be rubbed against the prominences.

It may be difficult to achieve a high washing effect demanded by consumers with only the rotary power of the drum. Thus, there has been proposed an air bubble washing machine capable of improving the washing effect by using air bubbles. The air bubble washing machine may incorporate therein an air bubble generator, and air bubbles generated by the air bubble generator may be supplied into the drum in the middle of a washing operation, to thereby improve the washing effect.

The drum type washing machine may be used to wash delicate clothing made of a delicate material such as pure cotton or linen. In such a case, the drum type washing machine may be operated in a delicate washing mode for washing the delicate clothing.

Since, however, the drum type washing machine washes the laundry using a relatively small amount of water, the laundry may be rubbed against the prominences in the drum more frequently than in cases of other types of washing machines such as air bubble washing machine. As a result, when washing delicate clothing, the clothing may become abraded (e.g., irregularly fluffy) or damaged.

A conventional drum type washing machine may be disclosed in International Patent Laid-open Publication No. WO 2008/091124 (published on Jul. 31, 2008).

SUMMARY

The present disclosure has been made in an effort to provide a control method for a drum type washing machine, capable of washing delicate clothing while causing less damage to the clothing.

One or more exemplary embodiments of the present disclosure provide a method for controlling a drum type washing machine, including selecting a delicate washing cycle (e.g., by receiving an input from a user); supplying air bubbles into a drum of the drum type washing machine, thus allowing delicate laundry and/or clothing to be separated or moved away from a bottom surface of the drum; washing the laundry while rotating the drum in a forward and/or backward direction (e.g., by rotating a shaft driven by a driving motor forwardly and/or backwardly); rinsing the laundry; and removing water from the laundry.

The delicate washing cycle is for delicate clothing including pure cotton or linen.

Air bubbles may be supplied when a rotational direction of the driving motor is switched during the washing step. In one or more embodiments, the air bubbles are not supplied into the drum while the driving motor is rotating the drum.

In various embodiments, the rotational direction of the driving motor may be switched a preset number of times in the washing step.

A plurality of prominences for improving the washing effect may be on the bottom surface of the drum.

The air bubbles may be supplied or jetted into a tub and drum containing the laundry, such that the laundry moves away or separates from the prominences.

According to exemplary embodiments, it is possible to provide a control method for a drum type washing machine, capable of washing delicate clothing while causing less damage to the clothing.

The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic cross sectional view illustrating an exemplary drum type washing machine according to one or more embodiments of the present disclosure.

FIG. 2 is a block diagram illustrating components for controlling the washing machine of FIG. 1.

FIG. 3 is a flowchart describing an exemplary control method for a washing machine equipped with a bubble generator.

DETAILED DESCRIPTION

In the following detailed description, reference is made to the accompanying drawings, which form a part hereof.

The illustrative embodiments described in the detailed description, drawings, and claims are not meant to be limiting. Other embodiments may be utilized, and other changes may be made, without departing from the spirit or scope of the subject matter presented here.

FIG. 1 is a schematic cross sectional view illustrating an exemplary drum type washing machine 1 in accordance with one or more embodiments of the present disclosure.

Referring to FIG. 1, the drum type washing machine 1 for washing delicate clothing in accordance with exemplary embodiment(s) may include a cabinet 10 that forms the exterior of the washing machine; a rotatable drum 20 in the cabinet 10 that holds laundry therein; a tub 30 outside and/or surrounding the drum 20 that holds water for washing the laundry; an air bubble generator 40; and a driving motor 50.

Lifters may be in two or more locations (e.g., at upper and lower locations) along the inner peripheral or cylindrical surface of the drum 20. The lifters serve to lift up the laundry and allow the laundry to drop back into the washing water in the drum 20 when the drum 20 rotates. Further, prominences 28 (such as embossing, or irregularities stamped, pressed or otherwise formed in the cylindrical surface of the drum 20) may be provided in the drum 20. When the drum 20 is rotated, the laundry in the drum 20 may be lifted up by the lifters 22 and then dropped down repeatedly. The laundry may be washed by the impact and/or force generated when it is dropped into the washing water.

Multiple dampers 32 supporting the tub 30 may be provided between a bottom plate or floor 12 of the cabinet 10 and the tub 30. The upper end of the tub 30 may be elastically connected to a top plate or panel 14 of the cabinet 10 by coil springs 34 (e.g., in the front and rear of the tub 30). A substantially horizontal balancing weight 36 may be fixed above the tub 30, at, near or between the coil springs 34.

Further, the drum type washing machine 1 may further include a door 16 through which the laundry is put into or taken out of the drum; a drum bracket 24 at and securely fixed to a closed end of the drum 20; a drum shaft 26 fastened to the drum bracket 24 and serving as a rotation shaft of the drum 20; and a bearing housing 28 accommodating therein a bearing that supports the drum shaft 26.

The driving motor 50 that delivers rotary power to the drum shaft 26 may comprise a BLDC (Brushless Direct Current) and/or DD (Direct Drive) motor having a gearless clutch (e.g., without a gear mechanism).

Further, a drain pump 58 configured to drain wash water through a drain hose 62 may be connected to a bottom surface of the tub 30.

An air bubble generator 40 configured to generate compressed air may be in a bottom portion of the cabinet 10, below the tub 30. Further, at a bottom surface or portion of the tub 30 is an air bubble disperser 60 configured to generate, form, release, and/or control a size of air bubbles by distributing the compressed air from the air bubble generator 40 into the drum 20. The bubble disperser 60 comprises a shallow, inverted tray-like piece having a mesh or a grid with relatively small holes therein for formation and/or distribution of the air bubbles through the holes. The bubble disperser 60 may have a length substantially equal to or slightly less than (e.g., 80-110% of) a depth of the drum 20, a width of from 1-30 cm (or any value or range of values therein), and a depth of from 0.5-5 cm (or any value or range of values therein). The holes in the bubble disperser 60 may have a width and/or diameter of from 100 μm to 5 mm (or any value or range of values therein), although generally, smaller is better for washing performance, and larger is better for throughput (e.g., volume of air through the distributor 60 per unit time) and manufacturing and maintenance costs. To facilitate substantially complete drainage of water from the tub 30, the bubble disperser 60 may have a plurality of holes at the contact interface between the bubble disperser 60 and the tub 30.

An ozone generator 70 configured to generate ozone from the compressed air from the air bubble generator 40 may be provided, and hoses 42 between the air bubble generator 40, the ozone generator 70, and the air bubble disperser 60 may transport the gases from one unit to the next. Alternatively, the ozone generator 70 may be a stand-alone unit, used in place of the bubble generator 40. Ozone may act as a mild oxidant, or bleach, in the washing process for delicate clothing and/or fabrics.

FIG. 2 is a block diagram illustrating components for controlling a drum type washing machine equipped with a bubble generator.

Referring to FIG. 2, the drum type washing machine 1 may include an input unit 100 through which operations for washing, rinsing and spin drying are selected, inputted and/or received from a user; a controller 200 configured to control the driving motor 50, the air bubble generator 40 and/or the ozone generator 70 (when present) according to preset programs in response to the selected operations; a memory 210 that stores information for the controller 200; a water supplying device 110 configured to supply water to the tub 30 under the control of the controller 200; and a drain 120 configured to drain the wash water from the tub 30.

The input unit 100 may include a control panel on the front surface or the top surface of the cabinet 10. The control panel may include a plurality of function and/or setting selection buttons and/or a display through which the user can select a washing cycle and change function(s) and/or setting(s). Through the input unit 100, the user may be allowed to select, among various washing cycles, a delicate washing cycle, having default settings appropriate for washing delicate clothing and fabrics. The controller 200 may receive a signal according to the user's selection of the delicate washing cycle and control the above-described components of the washing machine 1 in response to the signal.

The water supplying device 110 may be configured to supply water directly into the tub 30 or mix it with detergent before or while supplying the water to the tub 30. The water supplying device 110 may include a water supply pipe (not shown) connected to an external water source.

The drain 120 may be configured to drain the wash water from the tub 30 to the outside of the drum type washing machine 1 after washing, rinsing and the like are completed. The drain 120 may include the water drain pump 58 and the water drain hose 62.

In various embodiments, delicate clothing, fabric and/or material may refer to, by way of non-limiting examples, clothing made of pure cotton or linen, thin clothing, fluffy clothing (e.g., scarves, knit hats, blankets, coats, etc.), functional clothing for sports comprising high-price special materials (e.g., cycling shorts, stretch pants/shirts/shorts, knee/elbow/ankle brace/material, etc.), etc. However, the use of the delicate washing cycle may not be limited to washing these clothing. The user may select this delicate washing cycle for any clothing if they want to prevent damage to the clothing.

FIG. 3 is a flowchart for describing an exemplary control method for a drum type washing machine equipped with a bubble generator.

Referring to FIG. 3, a washing cycle is selected by a user (S100). This step of receiving an input or selection of the washing cycle (S100) may be performed before or after the user puts laundry into the drum 20 when actually using the drum type washing machine 1. Here, an exemplary embodiment will be described for the case of performing the step of receiving the input or selection of the washing cycle washing cycle (S100) after the laundry is put into the drum 20.

In the event that the selected washing cycle is a delicate washing cycle (S200), the controller 200 performs a delicate washing process in which air bubbles are supplied into the drum 20 before the drum 20 is driven by the driving motor 50. On the other hand, if the selected washing cycle is not a delicate washing cycle, the controller 200 performs a washing process corresponding to the washing cycle selected by the user (S400). When the delicate washing cycle is not selected, one or more valves in the bubble generator 40 and/or ozone generator 70 (e.g., in a manifold distributing the gas to the tubes 42) may be closed to prevent backflow of water into the tubes 42, the bubble generator 40 and/or the ozone generator 70.

If the delicate washing cycle is selected, and a command instructing the start of washing operation is inputted or received from the user through the input unit 100, the controller 200 supplies wash water into the tub 30 using the water supplying device 110 (S310). The water may be supplied into the tub 30 in a preset amount or to a preset water level, whereby the laundry in the drum 20 may soak in the water. Since the drum 20 is not rotated yet, the laundry in the wash water may sink due to gravity and come into contact with the prominences 28 on the inner surface of the drum 20.

When the supply of water is completed, the controller 200 supplies air bubbles into the drum 20 using the bubble generator 40 (S320). The pressure or flow of the air bubbles from the air bubble generator 40 may be sufficient to cause the laundry, which may be in contact with the prominences 28, move away or separate from the prominences 28.

The controller 200 may further include a sensor for detecting the weight of the laundry. In such a case, the pressure and/or flow of the air bubbles may be set differently, depending on the weight of the laundry.

The supply of the air bubbles may be performed for several seconds in order to release the contact state between the laundry and the prominences 28 (e.g., to keep the delicate laundry away from the prominences 28). By way of non-limiting examples, the air bubbles may be supplied for about 1 second to about 15 seconds (e.g., from about 1 second to about 4 seconds), and/or from a time immediately before changing the rotation direction of the drum to a time just after the rotation direction of the drum has been changed.

Upon the completion of the supply of the air bubbles, the delicate laundry moves away or separates from the prominences 28. The controller 200 stops the supply of the air bubbles, and then starts a washing step (S330) in which the drum 20 is rotated by rotation of the driving shaft 26 by the driving motor 50 forwardly or backwardly.

In the washing step (S330), the driving motor 50 rotates the drum 20 according to a preset sequence previously set in the memory 210, whereby the laundry is washed. At this time, since the laundry has moved away or separated from the prominences 28 by the air bubbles before the driving motor 50 is driven, friction between the laundry and the prominences 28 can be minimized, and friction between the delicate laundry and the bubbles (which can release energy when they burst, thereby increasing the washing efficiency) can increase. As a consequence, damage to the laundry from friction between the laundry and the prominences 28 may be prevented.

In the washing step (S330), the rotational direction that the driving motor 50 rotates the driving shaft 26 may be switched, and the number of switches or changes in direction and the timing for switching the rotational direction may be predetermined and stored in the memory 210. In exemplary embodiments, whenever the rotational direction of the driving shaft 26 is switched in the washing step (S330), the supply of air bubbles (S320) may be performed. While the air bubbles are supplied, the driving motor 50 may be stopped. That is, when the direction that the driving motor 50 rotates the shaft 26 changes from forward rotation to backward rotation or vice versa, the driving motor 50 may be temporarily stopped. When the driving motor 50 is stopped, the air bubbles may be supplied into the drum 20, allowing the laundry to move away or separate from the prominences 28. As a result, even when the rotational direction of the drum 20 switches in the washing step (S330), friction between the delicate laundry and the prominences 28 can be effectively reduced, so that damage to the laundry may be minimized

In the above-described embodiment(s), the driving motor 50 is operated and stopped repeatedly. When its operation is resumed after a stop, the rotational direction of the driving motor 50 may change from that in the prior operation, and when the driving motor 50 is stopped, the air bubbles may be supplied into the drum 20. The time for operating the driving motor (operation time) and the time for stopping the driving motor (stop time) may be set to a certain ratio or for certain lengths of time. The ratio between the operation time and the stop time in the delicate washing cycle may be smaller than a ratio between the operation time and the stop time in a standard washing cycle. As one example, in the standard general-purpose, typical, usual or basic washing cycle, the driving motor may operate for about 15 seconds and stop for about 5 seconds in repeated cycles. Meanwhile, in the delicate washing cycle, the driving motor 50 may operate for about 5 seconds and stop for about 10 seconds in repeated cycles in the washing step (S330). By supplying air bubbles to the tub and drum during the time in which the motor is stopped, the time period during which the laundry contacts the prominences of the drum 20 can be decreased. Therefore, damage to the clothing can be reduced.

Upon the completion of the washing step (S330), the controller 200 may perform a rinsing step (S500) and a spin drying step (S600), in sequence.

The rinsing step (S500) and the spin drying step (S600) are performed while the rotation rate (e.g., RPM) of the driving motor 50 varies according to a preset sequence. The average rotation rates of the driving motor 50 in the rinsing step (S500) and the spin drying step (S600) in the delicate washing cycle may be smaller than average rotation rates of the driving motor 50 in a rinsing step and a spin drying step in the standard washing cycle. Therefore, damage to the laundry may be reduced, minimized or prevented.

In the method for controlling the drum type washing machine according to the above-described embodiments of the present disclosure, when washing delicate clothing, air bubbles are supplied into the drum 20 before the drum 20 rotates, thus allowing the laundry to move away or separate from the prominences 28 on the inner surface of the drum 20. Accordingly, friction between the laundry and the prominences 28 can be reduced, so that damage to the laundry can be reduced, minimized or prevented.

From the foregoing, it will be appreciated that various embodiments of the present disclosure have been described herein for purposes of illustration, and that various modifications may be made without departing from the scope and spirit of the present disclosure. The exemplary embodiments disclosed in the specification of the present disclosure do not limit the present disclosure. The scope of the present disclosure will be interpreted by the claims below, and it will be construed that all techniques within the scope equivalent thereto belong to the scope of the present disclosure. 

What is claimed is:
 1. A method for controlling a drum type washing machine, comprising: selecting a delicate washing cycle; supplying air bubbles into a drum of the drum type washing machine; rotating the drum; rinsing the laundry; and removing water from the laundry.
 2. The method of claim 1, further comprising placing delicate clothing in the drum before air bubbles are supplied into the drum.
 3. The method of claim 2, wherein the delicate clothing is placed in the drum before the delicate washing cycle is selected.
 4. The method of claim 2, wherein the delicate clothing includes pure cotton, linen, thin clothing or material, fluffy clothing, or sports clothing.
 5. The method of claim 4, wherein the delicate clothing includes pure cotton or linen.
 6. The method of claim 1, wherein the drum is rotated during a laundry washing course.
 7. The method of claim 6, wherein the air bubbles are supplied when a rotational direction of a driving motor that rotates the drum switches in the washing step.
 8. The method of claim 7, wherein the air bubbles are not supplied to the drum while the driving motor is operating.
 9. The method of claim 7, wherein the driving motor rotates the drum in one of a forward direction and a backward direction for a first length of time, the driving motor stops rotating the drum for a second length of time, the driving motor rotates the drum in the other of the forward direction and the backward direction for the first length of time, and the driving motor stops rotating the drum again for the second length of time.
 10. The method of claim 9, wherein the air bubbles are not supplied to the drum while the driving motor rotates the drum in the forward direction or the backward direction.
 11. The method of claim 9, further comprising repeating rotating the drum in the one direction for the first length of time, stopping rotating the drum for the second length of time, rotating the drum in the other direction for the first length of time, and stopping rotating the drum again for the second length of time a predetermined number of times.
 12. The method of claim 7, wherein the rotational direction of the driving motor is switched a preset number of times while rotating the drum.
 13. The method of claim 1, wherein the drum has a surface comprising a plurality of prominences configured to improve a washing effect of the washing machine.
 14. The method of claim 10, wherein the air bubbles are jetted into the drum and/or a tub surrounding the drum to separate or move the laundry away from the prominences.
 15. The method of claim 1, wherein selecting the delicate washing cycle comprises receiving an input from a user.
 16. The method of claim 1, wherein supplying the air bubbles allows delicate clothing, laundry and/or material to move away or separate from an inner cylindrical surface of the drum.
 17. The method of claim 1, wherein the air bubbles comprise ozone, and the method further comprises generating the ozone.
 18. A drum type washing machine, comprising: a tub configured to hold water therein; a rotatable drum in the tub, configured to hold and wash laundry and/or clothing therein, the drum having a cylindrical surface comprising a plurality of prominences configured to improve a washing effect of the washing machine; a user interface with a delicate washing cycle selection button; an air bubble generator configured to generate air bubbles in the drum; a bubble disperser and/or distributor in the tub, configured to disperse and/or distribute the air bubbles in the drum; a motor configured to rotate the drum; and a controller configured to control the motor and the air bubble generator so that the air bubble generator generates air bubbles when the drum is not rotating, and the air bubble generator does not generate air bubbles when the drum is rotating.
 19. The drum type washing machine of claim 18, further comprising an ozone generator configured to receive air from the air bubble generator and supply ozone to the bubble disperser and/or distributor.
 20. The drum type washing machine of claim 18, wherein the air bubble generator comprises an ozone generator. 